Thiocarbamyl piperidyl sulphides



Patented Nov. 6, 1945 THIQCABBAM'YLPIPEMBY SULPHIDES Robert H. Cooper, Nitro, W. Va., assignor to Monsanto Chemical Company, St. Louis, Mo., a cora a poration of Delaware No Drawing. original applifcfimtibh t,

1940, Serial naes sso. *Diviil'ed ana -tins airplic'atioi'i Mil/y 26,1943, Serial NU. 48856! 1 Claim. (o1. 2 664- 295) The present invention relates to a new and improved class of rubber vulcanization accelerators, to a process of vulcanizing rubber or a rubber containing material and to the vulcanized rubber products obtained with the aid of said new and improved accelerators.

The accelerators of the present invention are the product's obtainable by the oxidative condensation of dithiocarbamic acids and primary or secondary amines More particularly the preferred easier accelerators, comprise compounds believed tof'possess the structure R x -M-ii where R and R" repiesent'ur'iivalent organic groups and may together iorrn asing'le divalent organ c gro p, Fbrexample and 13, may be the sensor flifieieritaIKSZL aiyt arai kyi or an; cyclic groups orai'e unitedtoiorfii a closed structure. xieisresnts hydrogen or a'iinivalent organic group arid-further may be combined with Y tod'orifr'a sifile organic divalent group, Y otherwise representing a univalent organic il 1 the preieirezi-fsspeets of the invention X is a member of a; group consistingofhydroge'n'; alkyl and aralkjyl radicals and iflsjsfilfifli near a group consisting of alkyl, aralkyl and V l l radicals or X anclYtogether Ioliiua valent organic radical. r

) Still more particularly it has the products derived from prin a'ry aminesffwitli one notable exception hereinaft that is to say compounds in whit possess accelerating properties stipe ways to the products derived from secondary i addition the, pi'eri'ed mass of competin are iiio'r''ativ at 16w temperatures'but at-tlf'le seine "ti-ililhalfflsis ena iicy, to previ ilcanize marine co iesebiiaiagamiii salts t th icoro be obtained by a Qarelul oxidation ofan aqueous admixture of a dithiocarbamicf acid, usually in oriseeonuary amine However, other methods of preparation may be employed were convenient or desirable. For example some secondary n is desired tolipint out that this inventionis not limitdito afliew dithiocarbamic acidslbnt that usefuleompoiin ds may be obtained-from any I dlthiocaibamic acid derived from a secondary .tlie 'fim of awater' solublesalt, and a primary dimetllyl thiocarbamyl propy diethyi amine; ai'phe yiamme and eqgi v ei tsanu anam'g'ues thereof.

, ile t is not meant to mply that rip-other amines give biiiuauvetondensauon products it 'eeiiyieuii i;;uiat rim ry and secondary an; tl an al'riinonia give excellent re: siult's ieactedwitpdithiocarbarhio acids in trieprese ice oi anoiliilizing a ent. However it is again desired to; eitiphaslze that other methods or preparation may be; uiilizeu desired since mistress-n inventionlimited to the fi er pyynientheiiew ems-s or accelerators H a l uitableafifineis comp se pipein dliie,-riibrplloiiiie, dimethylfa'rhine diethyl amine; dip'ropyl me; di-wbutyl amine, di isobutyl amine, dii'soarhyl ahiiiie; diplieriyl guanidine, di= benzyl amine, cyclohexylamine, benzyl amine, ethylene diamine, n=butyla1riine, n-amy1 amine, ethyl amine, p-ethyl cyclohexylamine, allyl amine, hexahydrobenzyl amine and iso butyl am ne t m t n inflame the preparation athe hewjaecelerators and a are to be understood. as illustrative of the invention Bu t m fi fiv thereof-1 L l its mpz'elz i l 'Iiitoasiiita'bl essi ther charged 183.2 paitstyweigii aii'aduous solution contamifig's bstaf tially 0;; mo ecula ropor on of slidiuifi dimethyl aiu ieeartafiiaia and 33 parts maintained at 45-51) Ci.tliif added over 2, periods: about '1Tr'1ifiuts substantially 330 parts by weight of a 10.16% "aqueous sodium hypochlorite solution; During the addition of the latter" sufficient 40% sulphuric acid was added to lzjeepgthepofieau Hemw' 700' mimvolts a determinedby' an ant mony, electrode in conjunction with a standard saiurateueaiomei hair cell, ifleasuremifltfbeing'i made with a suitable" platen tionieter: This corresponds to a pH less than about 12.3. After completion of the reaction the product was eiitracted from the aqueouevehicle by a suitable organic solvent as for example ether; the solvent extracts washed and the solventremoved byany convenient method. There was finally obtaineda pasty solid-believedto be cyclohexylamin'o sulphide of the formula V Nitrogen... 1. s

Analysis for sulphur and nitrogen gave the following results: 7 j x I, l 1

lalculated for O'HlaSzN: Fmmfi Nitrogen L. a 112.8 112. Snlnhnr 29. 3 27 Example II" Into a suitable reaction vessel there was charged 266.5 parts by weight of an "aqueous solution their composition verified by analysis for sulphur and nitrogen. i v

As specific embodiments of the invention showing the valuable properties of the new and preferred class of accelerators but without limiting the invention, a rubber stock wa compounded 'compnsmg Stock A, parts a V by weight Pale crepe rubber 100 Zinc oxide um?! F-f-f 7" 3 Stearic acid 0.5

containing substantially 0.25 molecular propor-= tion of sodium cyclopentamethylene dithiocarbamate and 27.5 parts by weight (substantially 0.27 molecular proportion) of cyclohexylamine.

To this mixture maintained at 46-51? C. there a we d We" a P ri d ui tw p r eu stantially 280 parts by weight of 10% aqueous sodium hypochlorite solution. During the addition of the latter suflicient 40%sulphuric acid was added to keep the potentialat about 660-765 millivolts, measurement being" carried outas in the foregoing examplel; After the addition of the h'ypoclilorite stirring was continued for about thirty .minutes'at' 5 "C. after which the Putt Y1 l e e s wh h ha S ais11 i d nd. washeduntil neutral. The product may beiur thenpurified by dissolving in ether,- filtering 01f.

' insoluble impurities" and removing thesolven'u' A g'oodyie'ld of awaxy solid believed to be cycle pent'ainethylene thiocaibaniyl 'cyclohexylal'nino sulphide was obtained." The percent'ffsulphur found 'by analysis was found by analysis was 24.1% as compared to 24.8% calculated for C12H22S2N2. I V f Example III -Into a suitable reaction vessel there -Was charged 266 parts by weight of an aqueous solu'-' tion containing substantially 0.25 molecular pro portion of sodiunr cyclopentamethylene dithiocarbamate and 24.6 parts byweig'h t (substantially 0.27 molecular proportion) of 395 Z; pipe'ridiner To this mixture maintained atabout'45 -50 C. there was added over a period of about 135 minutes 280 parts by weight of 10% aqueous sodium hypochlorite solution; Duringthe'additi'on of theflatter sufiicient 40% sulphuric acidwa's added to keep the potential at about 700-805 millivolts;

measurement being made as in the foregoingex g amples. After the addition of the oxidizing agent stirring was continuedfor about thirty minutes at C. after which'the charge was cooledand the; insoluble product filtered oil? and wa'shed'un' 'Dimethyl Vthiocarbamyl cyclohexylamino sulphide 0.5

The stock so compounded was cured by heating in a press at'the temperature of 20 pounds of steam pressure per square inch and found to possess the physical properties set forth below.-

Mogul/us pf elalstieity in Tensile at Ultimate I g g W break inv elongation, I, v I v lbs/in. i percent;

The above data show the desirable accelerating properties of the preferred class of materials and show more particularly that dimethyl thiocarbamyl cyclohexylamino sulphide is a powerful accelerator. I

Asfurther specific embodiments of theinvn f tion but again' without limiting the invention.

ere-me imp dioe e aa;

til'neutral'. When dry the" waxy 'solid'was" corn:

pletely soluble in etherand where a productjof higher purity 'is'desire'd-may be recrystallized from ether or other suitable solvent." Theprodnot appeared to be the expectedcyclopentameth ylenethiocarbamyl piperidyl sulphide as indicated by sulphur and nitrogen figures given'be' lowz' f Calculated f0? f uHaoSaNz V 11.5 1 11.6 Sulphur 26.; 26.0

Other typical examples of the invention com p e m t yl cy yl thiocarbamyl cyclohexy1 amino sulphide and dibenzyl thiocarbamyl cyclohexylamino sulphide which were prepared by the method set forth in the foregoing examples and Found Dlben zyl, thiocarbam'yl' I cyclohexylamino sulinhidp v I The stocks so compoundedwerefouncl to give good cures in either in 60min'utes atthe temperature of five. pounds steam pressure perfsquareiinchor in fi e minutes, a t e em e ature. r t enty Pounds of m r 's ure' nerL qua e inc ;:th cured rubber products, ;exhibt ingn1odulus and tensileprop'erties as follows;;

The above data show the desirable accelerating properties of the preferred class of accelerators. It will be further noted that cyclopentamethylene thiocarbamyl piperidyl sulphide possesses unusuall strong accelerating properties.

Further examples of the new class of compounds comprise F. Diamyl thiocarbamyl cyclohexylamino sulphide.

G. Diamyl thiocarbamyl benzyl amino sulphide.

H. Dimethyl thiocarbamyl di-n-butyl amino sulphide.

J. Methyl cyclohexyl thiocarbamyl di-n-butyl amino sulphide.

0.5 part by weight of the above compounds were incorporated into rubber stocks comprising 100 parts byweight of pale crepe rubber, 5 parts by weight of zinc oxide and 3 parts by weight of sulphur. The rubber compositions so prepared could be cured :by heating for thirty minutes at the temperature of twenty pounds steam pressure per square inch and provided vulcanized rubber products of desirable modulus and tensile properties.

The present invention is not limited to the specific examples hereirrbefore set forth wherein the preferred accelerators are employed. Other ratios of the compounding ingredients than those mentioned in the examples as well as other well known fillers, pigments and the like may .be employed in the production of various types of rubber compounds and are apparent to those skilled in the art to which the present invention pertains. The present invention is limited solely by the claim attached hereto as part or the present specification.

This application is a division of co-pending application Serial No. 364,599 filed November 6, 1940 now U. S. Patent No. 2,333,468.

What is claimed is:

Cyclo pentamethylene thiocarbamyl piperidyl sulphide.

ROBERT H. COOPER. 

